Electrophoretic analysis of natural populations of Leptosphaeria maculans directly from leaf lesions

Abstract

On oilseed rape, 207 leaf lesions attributed to Leptosphaeria maculans were classified as typical or atypical. Starch gel electrophoresis of glucose phosphate isomerase (GPI) performed on extracts of 229 leaf lesions comprising the 207 with L. maculans symptoms and 22 with Pseudocercosporella capsellae symptoms, yielded four different electrophoretic patterns of alloenzymes designated ET1 to ET4. In addition to ET1 and ET2, characteristic respectively of A-(highly virulent) and B-(weakly virulent) group isolates of L. maculans, the previously undescribed ET3 allozyme was recovered from a few typical and atypical L. maculans leaf lesions. The fastest ET4 allozyme was specific to P. capsellae. All but two typical leaf lesions produced the ET1 allozyme, whereas atypical lesions produced one of the three L. maculans allozymes. Occasionally a mixture of two allozymes was recovered from a same-leaf lesion. GPI electrophoresis performed directly on leaf lesions proved a useful and reliable method to identify L. maculans, and to differentiate between L. maculans and P. capsellae. This method of discrimination enabled deductions, from 377 leaf lesions analysed, about the structure of L. maculans populations on different oilseed rape varieties.

The first occurrence of stem canker on oilseed rape caused by Leptosphaeria biglobosa in Serbia

“…Further necrosis of inner tissue and delayed growth Figure 5. Pigment formation on liquid Czapek agar occurred in the second part of the vegetation period, which is in conformity with reports of Balesdent et al (1992) and Brun et al (1997). During the initial phases of growth on a PDA agar and afterwards, all tested isolates exude aerial mycelia grey-white in colour while substrate mycelia were milky white at first, as reported by Williams & Fitt (1999) and Fitt et al (2006).…”

“…During 2010, parasitic fungi were isolated from the base stem. The first symptoms were expressed in the form of irregular brown spots without the presence of pycnidia in accordance with the report of Brun et al (1997). Further necrosis of inner tissue and delayed growth Figure 5.…”

“…Pathogen L. biglobosa causes small brown spots with or without pycnidia in the spots Thürwächter et al, 1999). Balesdent et al (1992), Brun et al (1997) and West et al (1999) state that, apart from leaf blight, B group can also cause infestation of stem pith. Shortly after harvest, pseudothecia can be observed in the base parts of the stem, while a few weeks later it can be observed on the upper part of the stem (Hammond 1985 cit.…”

Intraspecific variability inPhomopsis azadirachtaeinfecting neem

“…Under standardized or uniform experimental conditions, the electrophoretic technique yields a unique characteristic protein pattern for a species of fungus that could be used, combined with other conventional criteria, for accurate identification of that species (Aggarwal et al 2001). Electrophoretic protein profile along with other conventional criteria benefited the precise identification of fungi at species level (Ho et al 1984;Ko and Ann 1985;Brun et al 1997). Electrophoretic data of soluble proteins provided effective markers for detection of hypovirulent isolates of Rhizoctonia solani (Girija et al 2000).…”

“…E-mail: sbsarpangala@hotmail.com Archives of Phytopathology and Plant Protection May 2009;42(5): 489 -498 Protein and enzyme patterns from mycelial extract were extensively studied in various fungi (Clare & Zentmyer 1966;De Vallavieille & Erselius 1984;Rajamannar et al 2000;Mohammadi et al 2004). Electrophoretic protein profiling of mycelial proteins was employed by several authors to differentiate many species and sub-species of fungi (Ho & Jong 1987;Bielenin et al 1988;Devaki 1991;Brun et al 1997;Aggarwal et al 2001). Identification and classification of strains and races of fungi were done utilizing electrophoretic technique of soluble proteins (Burdon & Marshall 1981;Desai et al 1992).…”